Irreversible reaction

Toluene to benzyl bromide (side-chain bromination)

C7H8+Br2C7H7Br+HBr

Direction
Irreversible
Processes
1
Stated as
Rate law
Heat of reaction
ΔH = -32,300 kJ/kmol (one process)
Element balance
Checked: balances
As the processes state itStoichiometry, conversions, heats of reaction and catalyst windows are taken from each process's files with their provenance. The build checks only that each process's equation balances in every element, from the process's own component formulas; it does not check the numbers. A process's design maturity applies to them.

Species

SpeciesNameCASRoleCoefficient
C7H8Toluene108-88-3reactant-1
Br2Bromine7726-95-6reactant-1
C7H7BrBenzyl bromide100-39-0product1
HBrHydrogen bromide10035-10-6product1

In the processes

  • Benzyl bromide by light-driven semi-batch bromination of toluene, HBr absorption and batch distillation (1000 t/a)Concept · not reviewed

    BNBR · Toluene to benzyl bromide (side-chain bromination)C7H8 + Br2 → C7H7Br + HBr

    Stated as
    Rate law
    Phase
    liquid
    Element balance
    Balances in every element
    Heat of reaction
    ΔH = -32,300 kJ/kmol at 298.15 K, as written (given: formation enthalpies at 298 K, HBr as gas: benzyl bromide (l) 16 +/- 2 kJ/mol (Ashcroft, Carson et al. 1963), toluene (l) 12.0 (Prosen et al. 1945), NIST WebBook (SRC-2); HBr (g) -36.3 (CRC table in chemicals 1.5.2, SRC-4) (D-005))
    Rate law
    basis: volume; driving: concentration; form: power_law; k: {"A":10.33,"Ea":30000}; orders: {"BR2":1,"TOL":1}; temperature range: 343.15 – 383.15 (assumed: ASSUMED effective photochemical rate (D-005, core limit L-1): no open kinetics of the light-driven bromination of toluene at plant scale found (2026-11-06); sized so that the bromine keeps up with a 5 h dosing at the lamps' photon budget; to be replaced by a photoreactor test with calorimetry)

Sources

What the processes cite for this reaction, each source once: for the reaction itself, its conversion, its heat of reaction or its catalyst. As the processes write them; DOIs, US patent numbers and web addresses are linked.

  1. PubChem CID 7498 (HSDB, Methods of Manufacturing): bromination of toluene under light (SRC-3)

    For the reaction · cited by Benzyl bromide by light-driven semi-batch bromination of toluene, HBr absorption and batch distillation (1000 t/a)

  2. US 3 528 899 A (1970): bromine dosed at the rate it reacts, so that little leaves with the HBr; product cut by distillation (SRC-1)

    For the reaction · cited by Benzyl bromide by light-driven semi-batch bromination of toluene, HBr absorption and batch distillation (1000 t/a)

  3. formation enthalpies at 298 K, HBr as gas: benzyl bromide (l) 16 +/- 2 kJ/mol (Ashcroft, Carson et al. 1963), toluene (l) 12.0 (Prosen et al. 1945), NIST WebBook (SRC-2); HBr (g) -36.3 (CRC table in chemicals 1.5.2, SRC-4) (D-005)

    For the heat of reaction · cited by Benzyl bromide by light-driven semi-batch bromination of toluene, HBr absorption and batch distillation (1000 t/a)